This invention relates to the progressive application of flexible sheet material, such as blanket insulation, to the purlins of a roof during the progressive construction of a roof of an industrial building. More particularly, the invention involves a carriage for carrying a reel of flexible sheet material along adjacent purlins of a roof and dispensing the sheet material onto the purlins in response to the movement of the carriage.
The roof structure of an industrial building typically includes inclined rafter beams that extend parallel to each other and horizontally oriented purlins mounted on the rafters that extend parallel to each other in a direction normal to the rafters. The purlins are supported by the rafters, and flexible sheet insulation such as fiber glass blankets are spread over the purlins. The lengths of the blankets extend normal to the purlins. Hard roof panels are applied on the insulation and connected to the purlins.
In recent years, flexible sheet material such as insulation blankets and vapor barrier sheets have been applied to industrial buildings by orienting the lengths of the sheets parallel to the purlins and placing the opposed side edges of the sheets on the tops of or close to the purlins so that the sheets span the spaces between the purlins. The vapor barrier sheets are positioned between the blanket and the interior of the building to reduce the introduction of moisture from the interior of the building to the roof structure.
In order to apply the sheet material, including blanket insulation, vapor barrier sheets and/or netting, to the purlins, a reel support carriage such as those disclosed in U.S. Pat. Nos. 3,559,914; 3,969,863; 4,075,807; 4,147,003; 4,967,535; 5,653,081; 5,653,083; 5,664,740; 5,685,123; 5,884,449; 5,921,057; 5,946,804; 6,003,282; 6,041,568 and 6,363,684 can be mounted on the purlins of the roof for supporting one or more reels of sheet material. The reel support carriage, sometimes known as a xe2x80x9croll stand,xe2x80x9d is guided by adjacent ones of the purlins and supports a reel of sheet material above the space between the adjacent purlins. The workers stand on the hard roof panels that already have been applied to the purlins and push the carriage with a push bar farther along the purlins to apply the sheet material as the sheet unrolls itself in response to the motion of the carriage. When the carriage has been pushed far enough away from the last applied roof panels, additional roof panels are applied to the purlins, and the procedure continues.
This procedure of applying sheet material to the purlins during the construction of a roof has the advantage of mounting the edges of the sheet material on top of the purlins or immediately adjacent the purlins so that there are no seams between adjacent insulation sheets that are directly exposed to the space below the roof. This is visually desirable and helps avoid the penetration of heat, moisture and other items carried by the environment within the building through the seams between the sheets to the roof panels, and tends to avoid deterioration of the roof panels.
Some of the problems with the use of carriages for applying sheet material to the purlins of a roof structure are guiding the carriage along the purlins, maintaining the carriage in proper position to apply the sheet material to the purlins, and maintaining the sheet material in a stretched configuration extending rearwardly from the carriage back to the position of the last applied roof panel so as to avoid the longitudinal sagging of the insulation material between the purlins before the next roof panel can be applied.
Another problem with the prior art carriages is that the typical roof structure has various obstructions that extend in or adjacent the path of movement of the carriages as the carriages progress along the purlins, and the carriages must be lifted over the obstructions. It is difficult to move the carriages over or about the obstructions and usually requires the carriages to be detached from their purlins, moved beyond the obstruction, and then reattached to the purlins so as to continue safe movement along the lengths of the purlins.
Another problem with the prior art carriages is that when there is a wind present, the wind is likely to disturb the sheet material extending from a carriage back to the position of the last applied roof panel, making it difficult to properly apply the insulation.
In some prior carriages there are one or more guides that extend downwardly from the carriage for engaging a purlin for the purpose of guiding the carriage along the purlins and holding the carriage in place on the purlins. However, the guide cannot be used when a another sheet, such as a safety net, has been previously applied to the same purlins since the space through which the guide extends has been covered or obstructed by the previously applied sheet.
It is to the solution of these problems that this invention is devoted.
Briefly described, the present invention involves a roof insulation applicator for applying flexible sheet material, such as blanket insulation, to a roof structure of an industrial building, whereby the length of the sheet is applied parallel to the purlins with the edges of the sheet resting on the top surfaces of the purlins or closely adjacent the purlins and fastened to the purlins.
In a preferred form of the invention, one or more reel support carriages are mounted to adjacent purlins of the roof before the roof panels are applied, and the carriage is moved progressively along the purlins. A reel support is mounted on the carriage for supporting a spiral reel of flexible sheet material on the carriage. The reel of flexible sheet material, such as heat insulation blanket made of, for example fiberglass or other particulate material, heat reflective sheet material, phase change material, netting, or a vapor impermeable sheet is supported by the reel support for dispensing from the carriage onto the upper surfaces of the purlins. A support roller is mounted on and extends laterally across the bottom of the carriage for supporting the carriage on adjacent purlins of the roof, and the carriage is tiltable about the support roller.
As the carriage is moved forwardly along the purlins, away from the previously applied roof panels, the free end of the flexible sheet extending from the reel supported on the carriage pays out from the reel, moves about the support roller and is applied to the top surfaces of the purlins at a position beneath the carriage. The opposed side edges of the sheet are applied to the top surfaces of the purlins by the support roller, and the support roller of the carriage rolls over these side edges, thereby urging the edges of the sheet into frictional engagement with the purlins.
The carriage and the reel support are configured so that the center of gravity of the carriage, the reel support and the reel of sheet material supported on the reel support is positioned between the rear of the carriage and the support roller. This applies a downward tilting force to the rear of the carriage about the support roller so that the rear portion of the carriage is urged downwardly and tends to rest on the purlins. This also causes the front of the carriage to tilt upwardly.
A purlin engager is mounted to the front of the carriage for slidably engaging the upper flange of one of the purlins on which the support roller engages. The purlin engager limits the lateral movement of the carriage with respect to the purlins, thereby holding the carriage on the purlins. The purlin engager also limits the upward tilting of the front of the carriage, and therefore limits the downward tilting of the rear of the carriage. The longitudinal offset of the center of gravity of the carriage from its support roller causes the weight of the assembly to apply leverage about the support roller, forcing the support roller into firm engagement with the upper surfaces of the purlins on which the carriage rests.
The additional leverage applied to the support roller by the offset center of gravity as described above adds additional downward force being applied to the edges of the sheet material against the upper surfaces of the purlins, thereby assuring that sufficient force is applied to the insulation material. This results in the sheet resisting forces of wind and weight so as to avoid sagging of the sheet between the purlins and inadvertent paying out of the sheet from the reel.
Strong magnets are mounted to the rear of the carriage in positions for being attracted to the purlins for urging the rear portion of the carriage downwardly toward engagement with the metal purlin. Since the sheet material will have been applied from the carriage about the support roller to the top surface of the purlin, the carriage and its magnets will not directly engage the purlins but the magnets will be attracted to the purlins through the sheet material. The force of the magnets is added to the weight of the carriage to trap the side edges of the sheet material against the purlins. This holds the sheet material on the purlins so that the sheet material tends to stay in its proper dispensed position on the purlins as the hard roof panels are being applied to the roof structure.
In some instances the purlin engager and the magnets will be used alternately, so that the purlin engager is used when the magnet is not used, and vice versa. The purlin engager can be used when the carriage is not being used to lay sheet material over another sheet and the purlin engager is able to reach beneath the plane of the upper flanges of the purlins to engage beneath the flange.
Also, the purlin engager can be adjusted so that it holds the front of the carriage on the purlin but does not limit the downward movement of the rear of the carriage. The longitudinal off set of the center of gravity of the carriage from its support roller causes the weight of the assembly to rest the rear of the carriage on the purlins, and the magnets at the rear of the carriage are attracted to the purlins when narrow sheets are being applied or through the edges of the sheet when the edges are to be applied to the tops of the purlins.
The support roller adds additional downward force being applied to the edges of the sheet material against the upper surfaces of the purlins, thereby assuring that sufficient force is applied to the insulation material at this position. This results in the sheet resisting the forces of wind and its own weight so as to avoid sagging of the sheet between the purlins and inadvertent paying out of the sheet from the reel.
When the carriage is advanced along the purlins to a position where an obstruction is in the path of the carriage, the operator can tilt the rear end of the carriage upwardly, breaking the magnetic attachment of the magnets with the purlins. If the purlin engager is being used, this results in a downward tilting of the front end of the carriage about the support roller. This downward tilting of the front end of the carriage also tilts the purlin engager downwardly, so that it can be easily removed from engagement of the purlin by rotating the carriage laterally, so as to laterally displace the purlin engager from the purlin. The carriage is now free to simply roll over or to be lifted over the obstruction. When the carriage is moved beyond the obstruction, again it is a simple matter of tilting the front end of the carriage downwardly so as to move the purlin engager back beneath the purlin, and then rotating the carriage slightly so that the purlin engager moves laterally beneath the upper flange of the purlin and tilting the carriage back to its normal attitude so that the magnet urges the rear of the carriage toward the purlins.
In order for a worker to control the movement of the carriage along the lengths of the purlins, a push pole is provided to the worker, so that the worker can stand on the previously installed hard roof panels and, by manipulation of one end of the push pole, engage the carriage with the other end of the push pole, and push the carriage along the purlins as needed. In addition, the carriage includes a pole lifting hook for engaging an intermediate portion of the pole so that the pole can be tilted upwardly by the operator against the lifting hook, causing the rear portion of the carriage to tilt upwardly, to break the attraction of the magnets with the purlins and to disengage and re-engage the purlin engager with the purlin. When the magnets are raised away from the purlins the carriage is free to be advanced along the purlins and to pay out more sheet material from the reel on the carriage.